Use the same blocks (modified) on the back for his name. Extending the 4 squares to equal the number of letters in the surname or first name which ever is longer. Make 2 blocks. Add a letter into each square to spell the first name (use blanks to center the name). Repeat letters in second block for surname.
Explain to the requester that you could not add these modified blocks to the top and this was the best workaround idea.
Lovely job!